The present invention relates to a cellular base station with intelligent call routing. In particular, the present invention is used in a cellular network to communicate with mobile stations and control the information routing to reduce network congestion and improve network performance.
Cellular communication networks typically employ base transceiver stations that communicate with mobile stations. When a mobile station (MS) initiates a call to the base transceiver station (BTS), it does so with an identification code. The BTS sends the identification code to a base station controller (BSC) and mobile switching center (MSC) for authentication. The MSC determines if the identification code matches one in a valid subscriber registry. Once authenticated, the BTS is authorized to communicate with the MS and the network places the call.
Ordinarily, this procedure is efficient. For example, when a MS wishes to communicate with a person at home, via land line, the mobile transmission is routed through the base station, BSC, MSC, public switch telephone network (PSTN), and then via land line to the person at home.
However, when one MS wishes to communicate with another MS, the communication is still required to route through the MSC. This type of routing is not efficient because it reserves a portion of valuable BSC, MSC, and sometimes PSTN resources for the call. Moreover, when the base station employs a transcoder rate adapter (TRAU), a private branch exchange (PBX), or other subsystems, a portion of those resources are also reserved for the call.
Hence, one limitation of existing cellular communication networks is that the BTS and BSC must always communicate with the MSC in order to place a call from one MS to another. Moreover, this routing may require a rate adaptation even when the two MS are operating at the same rate.
Another limitation of existing cellular communication networks is that they employ dedicated hardware that lacks flexibility. For example, the BTS and BSC may be required to route calls to the MSC whether this routing is most efficient or not. As another example, these networks may impose rate adaptation on all communications to match a standard rate (e.g., 64 Kbps), whether adaptation is necessary or not.
Still another limitation of existing cellular communication networks is that they lack flexibility to incorporate advanced features such as call routing in the BTS and BSC. These networks lack the ability to be scaled and modularized, and lack the flexibility to perform multiple tasks. Moreover, since existing communication networks use a great deal of dedicated hardware, a fault can cause data loss, or even cause the network to malfunction. When a BTS or BSC is broken, the network must operate in a reduced capacity, if it can operate at all.
The present invention relates to a cellular base station with intelligent call routing. In particular, the present invention is used in a cellular network to communicate with mobile stations and control the information routing to reduce network congestion and improve network performance. Exemplary embodiments are provided for use with the Global Systems for Mobile Communication (GSM) protocol.
A base station communicates with a plurality of mobile stations over a cellular network. In one embodiment, the base station includes a transceiver configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. The transceiver equalizes and decodes the inbound information and encodes the outbound information. The transceiver is coupled to a data bus for communicating the inbound and outbound information with the other elements in the base station. The transceiver is also coupled to a control bus. A trunk module is coupled to the data bus and to a mobile switching center. The trunk module communicates inbound and outbound information with the transceiver and the mobile switching center. The trunk module is also coupled to the control bus. Finally, a cellular central processor is coupled to the control bus to control the transceiver and the trunk module.
In another embodiment, the base station may include a plurality of transceivers, cellular central processors, and trunk modules. The base station architecture is modular and scalable. As a result, the base station can be modified to perform a variety of tasks and scaled to accommodate various performance requirements. For example, a low performance base station may have only one transceiver, one cellular central processor, and one trunk module. A high performance base station may have several transceivers, cellular central processors, and trunk modules.
Advantages of the present invention include modularity, scalability, distributed processing, improved performance, reduced network congestion, fault tolerance, and more efficient and cost-effective base stations.